Power-driven ski



Jan. 13, 1953 S. VAN VOORHEES POWER-DRIVEN SKI ll Sheets-Sheet 1 Filed May 19, 1950 STANLEY VAN VOO/PHEE-SI INVENTOR.

ATTORNEK A TTORNEK m lmil l1 Sheets-Sheet 2 STANLEY VAN VOORHEES,

S. VAN VOORHEES POWER-DRIVEN SKI A l H HJ Jan. 13, 1953 Flled May 19, 1950 Jan. 13, 1953 s. VAN VOORHEES POWER-DRIVEN SKI ll Sheets-Sheet 5 Filed May 19, 1950 NS \wv kno STANLEY VAN VOORHE'ES,

IN V EN TOR.

A TTORNEY.

Jan. 13, 1953 s. VAN VOORHEES POWER-DRIVEN SKI ll Sheets-Sheet 4 Filed May 19, 1950 STANLEY VAN VOORHEES,

lNl/ENTOR.

Br f ATTORNEY.

Jan. 13, 1953 S. VAN VOORHEES POWER-DRIVEN SKI ll Sheets-Sheet 5 Filed May 19, 1950 STANLEY VAN l/OORHEES,

INVENTOR.

ATTORNEK Jan. 13, 953 s. VAN VOORHEES 2,625,229

POWER-DRIVEN SKI Filed May 19, 1950 ll Sheets-Sheet 6 .9 STANLEY VAN VOORHE'ES,

INVENTOR.

A T TORNEK Jan. 13, 1953 s. VAN VOORHEES POWER-DRIVEN SKI ll Sheets-Sheet 7 Filed May 19, 1950 STANL EV VAN VOORHEES,

INVENTOR.

A TTORNEV.

Jan. 13, 1953 s. VAN VOORHEES POWER-DRIVEN SKI ll Sheets-Sheet 8 Filed May 19, 1950 STANLEY VAN VOORHEES,

INVENTOR.

ATTORNEY.

Jan. 13, 1953 s. VAN VOORHEES POWERDRIVEN SKI ll Sheets-Sheet 9 Filed May 19, 1950 STANLEY VAN VOORH'E'S,

INVENTOR.

ATTORNEY.

Jan. 13, 1953 s. VAN VOORHEES POWER-DRIVEN SKI Filed May 19, 1950 ll Sheets-Sheet 1O Jan. 13, 1953 s. VAN VOORHEES 2,625,229

POWER-DRIVEN SKI Filed May 19, 1950 11 Shets$heet 11 l 2 is 26 202 202 209 Z0424; my 2 STANLEY VAN VOO/PHEES,

IN VEN TOR.

ATTORNEY- Patented Jan. 13, 1953 UNITED STATES PATENT OFFICE POWER-DRIVEN SKI Stanley Van Voorhees, West Los Angeles, Calif.

Application May 19, 1950, Serial No. 162,982

24 Claims. 1

This invention relates to skis and more particularly to a ski having power means for propolling or driving the ski over a snow covered surface.

Various means have been heretofore proposed for either assistin the skier upwardly over a snow covered slope or for carrying him upward over an inclined terrain. In the first category may be mentioned removable climbers which consist of devices adapted to be slipped over or detachably mounted over the gliding surface of the ski. These climbers are provided with bristle-like elements which are adapted to lay substantially flat against the snow-engaging surface as long as the ski is forwardly moving but which move into an outwardly extending position relative to the surface upon backward movement of the ski. The bristles, in the outwardly extending position, form friction elements which bite into the snow to at least retard backward movement of the ski to which they are attached.

Skis equipped with such climbers aid the skier in climbing for, although they do not appreciably retard forward movement of the skis, they do act to resist backward movement of the skis. Thus a skier may, by alternately forcing his skis forwardly over an inclined terrain, climb that terrain. Obviously all energy required to lift the skier and his equipment up the terrain must come from the skier himself. Needless to say climbing a slope with even skis equipped with climbers is a laborious effort.

Ski tows and other similar facilities have been introduced for carrying skiers upwardly over inclined terrain. Although such facilities are extremely costly, they are widely used today in all popular skiing resorts. A skier using such facilities must obviously limit his skiing activities to the terrain immediately edjacentthe same unless he wishes to laboriously climb slopes by the use of climbers.

It has long been an appetency of the art to provide a ski which in itself provided means for driving the skier either forwardly over level terrain or upwardly over inclined terrain with little or no exertion of energy on the part of the skier. The ski of the present invention fulfills this long felt want for, without in any way impairin the gliding action thereof, the ski includes means for riving the same forwardly even over upwardly inclined snow covered surfaces.

The skis of the present invention, like conventional skis, are each formed with the usual surface for gliding over snow covered terrain and this surface is used in traveling downwardly over inclined surfaces in exactly the same manner as conventional skis are used. In all embodiments of the present invention herein illustrated, however, the gliding surface of the ski is displaced from its operative position for replacement by a driving or propelling surface whenever the terrain is such that the skier can no longer glide under the action of gravity.

The driving or propelling surface is actuated by a suitable source of power capable of supplying energy sufficient to propel the skier forwardly and upwardly on an inclined snow covered surface without the exertion of energy by the skier. Once the skier has been propelled to terrain down over which he may glide, the gliding surface is again brought into operative position and the driving means rendered inoperative to permit the skier to glide downwardly as with conventional skis.

The driving unit in all illustrated embodiments of the present invention comprises a pair of endless driving belts longitudinally arranged on each ski and spaced apart to permit the skiers boot to be mounted intermediate the adjacent ends of the longitudinally arranged belts. A suitable motor supplies power to one belt and power is preferably taken from the driving means of that belt to drive the other. belt through a conventional power transmitting means suitably arranged to carry out the desired end result.

The motor may be mounted directly on each ski or may be supported by a shoulder pack and connected through a flexible drive shaft to the drive element of the belt to be driven thereby. In the latter case, a motor for each ski might be used or, if desired, a single power unit could be provided for driving both skis. Obviously where the power unit is not separate from the ski, a unit for each ski must be provided.

The driving belts of each ski are supported by pulleys carried by bracket members cletachably mounted to the body member of the ski to the end that the entire driving unit can be removed if desired. Thus a skier may remove from each ski its driving unit and, once the driving unit is removed, the ski of the present invention very closely resembles a conventional ski and can be used as such.

The pulley of the driving unit which is driven by the power unit is held against movement relative to the ski body by the bracket member which supports the same for rotation. The remaining pulleys of the driving unit, on the other hand, are each movable relative to the bracket to which each pulley is mounted for rotation. To fix the distance between the axes of rotation of each pair 3 of pulleys and to hold the belt running thereover substantially taut in all positions of the pulleys relative to the body member of the ski, rigid frame members interconnect the axles of each pair of pulleys and thus prevent relative movement of the pulleys of each pair. The adjacent pulleys oi the two sets of pulleys are interconnected by a rigid link in those embodiments of the invention where the one belt is driven by a chain drive from the driven pulley of the other belt.

As only the pulley which is driven by the motor unit is held against movement longitudinally of the ski, all stresses imposed by the belts are taken by the body member of the ski through the bracket which mounts the driven pulley. As the brackets carrying the other pulleys of the drive unit permit some movement of the pulleys relative to the body member of the ski, the latter may flex in the same manner that a conventional 'ski will flex as it moves over irregular terrain.

In some embodiments of the invention herein illustrated and described, the fore and aft end portions or the body member of the ski are pivotally mounted relative to that portion of the ski body to which the boot oi the skier is mounted. in these embodiments, the fore and aft segments can be moved at least 180 degrees to present either the gliding surfaces of the segments or the driving surfaces to the snow covered terrain over clamped and in this embodiment, the entire ski is pivotally moved about its longitudinal axis to present one or the other of the surfaces. In the embodiment of the invention just mentioned, the boot clamping means must be inverted as the ski is inverted.

Other features and advantages of the present invention will be hereinafter apparent from the following description, particularly when taken in connection with the accompanying drawings, in which I Figure l isa sketch showing a skier equipped with the embodiment of the invention in which the motive power is carried by the skier and is transmitted to each ski through a flexible shaft;

Figure 2 is a top plan view of the left ski in the gliding position;

, Figure 3 is an elevational view of the ski of Figure 2 in the gliding position;

Figure 4 is an elevational view of the ski of Figure 2, but here shown in the climbing position;

Figure 5 is a plan view on an enlarged scale of the forward segment with a portion of the driving belt removed to more clearly illustrate parts hidden thereby;

Figure 6 is a section taken along line 5-5 of Figure 5;

Figure '7 is afragmentary view of the forward end of the ski showing the tip member reversed for c mbing use;

Fi ure 8 is a section taken on line E3 of Figure '7 Figure 9 is a plan view of the central portion or the ski showing the binding plate in a gliding position; I

Figure 10 is an elevational view of the central portion of the ski showing the binding plate in the gliding position; v

Figure 11 is a View similar to Figure;10 but showing the driving belts in operative position;

Figure 12 is a section taken along line I2--l2 of Figure 10;

Figure 13 is a section taken along line 13-! 3 of Figure 11;

Figure 14 is a section on an enlarged scale taken along line t4|4 of Figure 10;

Figure 15 is a section on an enlarged scale taken along line l5i5 of Figure 2;

Figure 16 is a section onan enlarged scale taken along line Iii-16 of Figure 10;

Figure 17 is a fragmentary perspective view of the medial portion of the ski with the binding plate shown in a gliding position;

Figure 18 is a perspective view showing the driving belts in operative position and the binding plate in the low position for climbing;

Figure 19 is a view similar to Figure 18 but showing the binding plate in the high position for climbing;

Figure 20 is a fragmentary, perspective view of a driving unit of the present invention mounted to a conventional ski;

Figure 21 is a top plan view of the central section of a. modified form of the ski in which the power unit is carried by'the ski;

Figure 22 is a fragmentary elevational view partly in section further illustrating the power unit of the embodiment of the ski shown in Figure 21;

Figure 23 is a view similar to Figure 21 but showing a modified form of the ski;

Figure 24 is a section taken along line 2 3-2 of Figure 23;

Figure 25 is a longitudinal section of one form of the driving belt;

Figure 26 is a view similar to Figure 25 but showing a modified form of the belt;

Figure 27 is a fragmentary plan view of the inner surface of a'modified form of the driving belt;

Figure 28 is a section taken along line 2328 of Figure 27;

Figure 29 is a View similar to Figure 27 but showing a still further modified form of the driving belt;

Figure 30 is a section taken along line 39-30 of Figure 29; and

Figure 31 is a section'tak'en along line 3l'3l of Figure 30.

Referring now to the drawing, Figure 1 illustratcs a skier equipped with a pair of skis'of one embodiment of the present invention. Each ski of the embodiment of the invention shown in Figure 1 comprises a body member including a binding plate H] for supporting the boot H of the skier. The boot is clamped to the plate 10 by means of an adjustable width toe iron 12 detachably'mounted to the binding plate and adapted to receive the'toe of the boot. A cable binding I3, which includes a resilient section M, is adapted to extend about the heel of the boot to removably hold the toe of the boot I I within the toe iron.

I The toe iron [2 comprises a substantially U- shaped body member, the flanges [5 of which engage the opposite edge faces of the binding plate I0. Each flange i5 is formed with a pair of L-shaped slots 16 adapted to receive spaced pins 1 I outwardly projectingfrom each edge face of the binding plate I0. The one leg of each slot l6, as clearly shown in Figure 2, opens onto the lower edge of the flange l5. Thus, the pins I! projecting from each edge face may be simultaneouslyiengaged within the leg opening onto .the edge'ofithe fiange,"'after which the toe iron is forced downwardly and then rearwardly to relathick? move the pins I] fsim'ultaneous'lyinto the other leg of each of. the' slots l6." 'Afterfthe' binding plate has been thus attached, aLthre'aded stud or bolt [8 is threadediinto a tapped opening formed in the edge'faoe of the binding plate to lock or hold the toe ironagainst movement. It should now be seen thatthe toeironca'n be quickly removed from the binding'plate vby merely threading 'out'the. bolt [Band then'slidin the toe iron forwardly to move'each pinl'l rearwardly in the one leg of each L -'sh'a'p.ed slot after which the toe iron may? be merely liftedzfrom the binding plate. The pins areso' carriediby the binding plate II] that thetoe ironjc'an'be mounted to veither face of the plate. The reason: for this arrangement will be further explainemhereinafter. 7 V .c 1 1;

The binding plate [0 is pivotallytmounted between the adjacent ends of a pair ofskis'iegmehts i9 and 2| held in a spaced apart but longitudinally' aligned attitude. byv alrigid yoke 22'. 1 The opposite ends oftheyok'exizi. are fprm'ed :with gusset plates '23 which are rigidly 'fixed by some conventional fastening means, lSuChlaS cap screws or thelike, to the adjacent :ends of the. ski segments l9 and 2|. Each'guss'et plate"23 .is formed with an upstanding flange-24 presenting inwardly facing planar surfaces cfacewiselyflengaged, by pivot plate 25 carried atLthe opposite-sends. ofthe binding plate ID. i The. pivot .plates25are. .each formed with an aperture which, when brought into registry with an apertiirefonnedinbach of thecflanges 24, form" a passageway for receiving an elongate shoulder bolt;26. The bolts,iwhen received within the passageway; form 'aligned pivot pins for mountingthe *binding plate Inforpivotal movement .upon an axis substantially coincident, with the longitudinal axis of thef aligned ski segments l9 and :21 Each of'ithe bolts .25 are secured against llaccidental (withdrawing movement by a conventionalnut as ,shown,:al though other means obviously could :be used:

The ski segments l9 and 2| are formed with glidingfaces 2! and 28respectively,as. are conventional skisitodayr 'The .bindingzplate 1'0 is also formed with a smooth planar Isurface'VZQ which, when the binding plate isiin the position shown in Figure 3;, forms .a'rsubstantial continue ation of the gliding'sjurfaces'of theiski'segments I9 and! l. It. should now be 'seen ,:ref'erring par ticularly to FigureB', that when the binding plate It} i in the position.shown"in that figure, the ski segments I9 and 2| and the'binding'plate .lll' present at the lower. face thereof .a conventional gliding surface adapted to r be brought -'i1ito' engagement with a snow covered terrain to permit the skier to glide downwardlythereover. Thus a skier, by securing his boots in' toe irons secured to the binding plate as shown in Figure 3; may use the ski of the embodiment of the present invention now being described, in exactly the-same way as conventional skis are used.

To hold the binding plate lOtin the position desired, the flanges 24 of the gussetiplate's 23 are preferably formed with spaced openings 30 adapted to receive spring'eloadedi'pins' 30 slidably carried by the pivot plates 25 of the binding'plate Ill. 1 The pins are formed: with upstanding actuators 30 passed through-slots formed in the pivot plates 25; The actuators permit the pins to be easily withdrawn from the openings in the flanges .24 to free the'plate lfl foi' pivotal movement The pins 30,1however When" engaged in the openings of the flanges 2mm h'old theplate in either :one of the tworalternate' positions amaterelative to the ski segments iiiand it, These two positions will be clear from a comparison study of Figures 3, 4, l2, and 13. a

. A skier today equippedqwith conventional-skis to climb a slope must either usetheso-called climbers or ski tows or other facilities for bodily carrying skiers upwardly over inclinedterrain. The skier thus is limited to either aslope which he'can himself climb, or to slopes over which he may be mechanically towed or carried. This obviously limits the activities of the skier. A skier equipped with the skis ofthe present invention is not so limited for, in all embodiments herein illustrated, means are providedfor driving the skier either forwardly over level-terrain or upwardly over inclined terrain 1 This means, in the embodiment of therpresen invention now being described, comprises an endless traction belt mounted to each ski; segment and driven by a power source carried by the skier. Returning now to Figure l, a small gasolinepowered motor may be used to drive the beltand such a motor is shown at 3| inthe figure referred to. The motor 3! may be conveniently mounted by a suitable shoulderpack 32 to the body of the skier and its poweroutput carriedto each ski by a conventionalpower transmitting flexible shaft 33. The one end of each flexible shaft 33 is suitably connected to the driven element of the motor while the oppositeend of each shaft carries a disconnect 331 adapted to be drivingly connected to an ax1e34 915a 12141163 35 mounted to the aftsegmentil; througha U-shaped bracket 36. An endless beItBLpassed around the pulley 35, isalso passed arounda second pulley 38 rotatably supported by abra'cket 39 mounted adjacent to the trailing edge of aft segment 2!. The belt 3'] is, theref ore, mounted to the segment to extend longitudinally thereof, but spaced from the surface thereof opposite to the gliding surface 28. I 7 Each of the brackets 36 and 39 is removably secured to the ski segment by identical means and, to simplify the disclosureof the presentinvention, the now preferred means used to secure the bracket 36 will only be described The securing means, as best shown in Figureldggomprises a pair of flanges 4| adapted toengage the oppositeedge faces of the ski segment. The; segment carries, at least on one side thereof,;a -pair of spaced spring-loadedpinsfl, each having a longitudinally extending finger 43 adapted to be secured in an opening formed in 'the fiange 4| engageable with the edgeface of the segment, 7 To mount the bracket to the segmentthe fingers 43 of the pins 42 are forced inwardly against-the springs urging the pins 42 outwardly until theend faces of the fingers are substantially flush'with the edge face of the segment. The flanges 4| may now be slipped over the segment and the openings in the flange brought into registry with the fingers 43. Once the iopening's" in the flange are brought intoi egistry with the fingers 43 and the latter released the springs will urge the same outwardly to; dispose the fingers within the openings of the p ng it should be obvious that to remov e the bracket, it would only be necessary to againurge the-pins inwardly to clear the fingers 43 from the openings in the flange 4i, afterlwhich the .bracketcanibe merely lifted fromtliesegmentL r". Referring again F ig ire1 l,'"it will be "se'en that "the opposi-te'ends of the a x le Qi" shaft s'g arje journaledinbearingelements 44 carried byibosses L45 'forming the 'terminal poitibrisef tiilamis of the U-shaped bracket 36. The pulley 35 includes a hub member 46 having an annular flange 41 to the opposite faces of which are bolted or otherwise secured sheave-like members 49 which form the body of the pulley 35. The hub member 46 may be fixed to the axle 34 for rotation therewith by a set screw, such as indicated at 49, although other conventional means obviously could be used. Each member 43 also includes a cylindrical element 59 which loosely sleeves the axle 34.

The periphery of the flange is serrated or toothed, as indicated at BI, and forms a sprocket wheel drivingly engaging a chain 52 fixed to the medial portion of the inner surface of the belt 31 by means of spaced angle bars 53 which support the hinge or pivot pins interconnecting the links of the chain, the bars 53 being riveted or otherwise secured in spaced relationship around the belt 3?. Also fixed to the inner face of the belt 31 are a pair of endless V-belts 54 of some suitable material, such as rubber. The V-belts 54 are fixed at opposite edges of the inner surface of the driving belt 37 and track in V-shaped grooves 55 formed in the cylindrical surface of each sheave-like member 48.

The bracket 39, which rotatably supports the pulley 38, referring now to Figure 15, also comprises, as will be remembered, flanges identical to the flanges 4! of the bracket 35. The bracket 39 is thus removably mounted to the ski segment by means identical to the means used to mount bracket 35. The pulley 33 is rotatably mounted to a fixed or stationary axle 56, the opposite ends of which are passed through aligned elongate openings 58 formed in the opposite arms of the bracket 39. The pulley 38 is rotatably mounted on the axle 56 through bearing members 59 fixed to the opposite sides of sheave-like members 69, bolted or otherwise secured to a sprocket wheel 5!, the teeth 52 of which are adapted to engage the drive chain 52. The sheave-like members 59, like the members 43, are each formed with a V-shaped groove 57 for receiving the endless V-belts 54 secured to the inner surface of the driving or traction belt 31.

The opposite end portions of the axle 55 are fixed in aligned openings formed in rearwardly extending arms 94, arranged at opposite ends of the pulley 39 by any conventional means desired, such as set screws similar to that used to fix the hub 46 to the axle 34. The arms 64 form a part of a rigid frame member 65 provide-:1 with laterally arranged web elements 66 joining longitudinally extending elements 61. It will be seen, referring now to Figure 2, that the longitudinally extending elements 91 are arranged at opposite sides of the driving belt 3? and that the laterally extending web elements 66 are arranged intermediate the two stretches of the belt 3'1.

The frame member 65 also includes a pair of arms 68 carrying bearing members 69 rotatably engaged with the axle 34. Thus the'frame member rigidly interconnects the axles 34 and 56 and fixedly determines the distance between the axes of rotation of the pulleys and 38.

It should now be seen that the output of the gasoline motor 3i, transmitted by the flexible shaft 33 to the axle 34, will drive the axle 34 and consequently the pulley 35. As the pulley 35 is rotatably driven, the teeth of the flange 47, engaging the links of the chain 52 fixed to the inner surface of the belt 31, will drive the belt in the path defined by the pulleys 35 and 38.

. Referring now again to Figure 14, the axle34 at the end opposite to the end connected to the flexible shaft 33 carries a sprocket wheel. II, the hub I2 of which is fixed to the axle 34 by a set screw 13. The teeth of the sprocket wheel H are adapted to engage and drive a sprocket chain I4 also passed about a sprocket wheel 15, the hub of which is fixed to an axle I6 by a set screw I7. The axle I6 is rotatably supported by a U-shaped bracket I8, removably mounted to the end portion of the ski segment I9 by spaced flanges identical to the mounting flanges II of the bracket 36. Spring-pressed pins, identical to the pins 42, hold the mounting flanges of the bracket I8 to the ski segment I9 but yet permit its removal therefrom as is bracket 36 removable from ski segmenti I.

Bracket I8 differs from bracket 36 in that the arms I9 of the former are provided with aligned elongate openings SI for passing the opposite ends of the axle I6 and carriage hub. The major axis of the openings 81, as clearly shown in Figure l, are substantially parallel with the fore and aft axis of the ski. To reinforce the defining edges of the openings 9|, outturned flanges 82 are formed on each arm of the bracket. Nested within each elongate opening 9| is a cylindrical bearing support 83 in which is fitted a pair of bearing members 84 for rotatably supporting the opposite ends of the axle 16. The bearing supports 83 form a part of a frame member 85 which will b hereinafter more fully described.

Fixed to the axle I6 is apulley 86, identical to the pulley 35 previously described. The pulley 86, like the pulley 35, comprises a hub member 81 fixed to the shaft or axle I6 by a set screw and includes an annular flange 89, the periphery of which is formed as a sprocket wheel. The teeth of this sprocket wheel engage a sprocket chain 9| fixed to the inner side of a traction belt 92 through spaced angle bars 93 as was th chain 52 of the belt 37. The belt 92 i identical to the belt 31 and includes a pair of spaced V-belts 94 adapted to engage in their travelabout the pulley 86 in V-shaped grooves 95 formed in the cylindrical surfaces of sheave-like members 96 bolted or otherwise secured to the opposite faces of the annular flange 99.

The belt 92 extends forwardly of the ski segment I9 and is rotatably supported at its forward end by a pulley 93 identical to the pulley 39 and supported for rotation on an axle I90, the opposite ends of which are passed through elongate openings I9I formed in a bracket I92 identical in all respects to the bracket 39. As the bracket I92 is identical to the bracket 39 and as it supports the pulley 99 in exactly the same way that the bracket 39 supports pulley 38, the structure thereof will not be again described.

The axle I99, like the axle 56, is actually stationary for the opposite ends thereof are suitably secured to forwardly extending arms I93 of the frame member 35, which, it will be remembered, carried the bearing supports 83 to which the bearing members 34 supporting the axle I6 were carried. The frame member 85 comprises longitudinally extending elements I94 arranged on opposite sides of the belt 92 and joined by transversely, as well as diagonally extending, web members I95 and 196 respectively. It should be seen now that the frame member 85 fixes the distance between the axes of rotation of the pulleys 66 and 99.

Fixed to each cross web I05 of the frame 85 are bracket members I91, each formed with oppositely extending pairs of arms I98. Each pair of arms I98 rotatably support an axlalflt carrying at the opposite ends thereof idlerpulleys I I adapted to receive and support the -V-be1ts 94 secured to the inner surface of -the belt -92. The arms I08 of each bracket III'I are resilient and tend to hold the V-belts 94 and consequently the driving belt 92 outwardly or away from the ski segment. The purpose and function of the spring mounted idler pulleys III'I will be made clear after the function of the driving belt 92 is understood. p 7

Although not shown, identical spring mounted idler pulleys are also mounted by bracket members, identical to bracket members I 01, to the frame 65 and cooperate with the v-belts 54 to hold the traction belt 3'! outwardly or away from the ski segment 2|.

To fix the distance between the axes of rotation of the pulleys 35 and 88, a rigid stress-carrying link II2, carrying at its opposite ends identical bearing members H3 which rotatably engage the axles 34 and I6, is used. The bearing mem ber II3, engaging the axle 34 as clearly shown in Figure 14, is disposed between the sprocket wheel II and the boss 45 while the bearing memHeT'I I 3, rotatably engaging the shaft I6, is disposed between the sprocket wheel I5 and the bearingsifiaport 83 in which is fitted the bearing member 84. The link II 2 extends betweenthe axles 34 and I6 in a position overlaying the yoke 22 and, as will be understood, rigidly fixes the dietaii'e'e between the axes of rotation of the pulleys and 86. r I

In the use of the skis of the embodiment ,of the invention shown in Figure 1, ithas already. been explained that when the mounting or binding plate I II is in the position shown in Figure 3, that is, with the gliding surface 29 thereof substantially flush with the gliding surfaces 21 and 2B of the ski segments I9 and 2| respectively, the ski is used as a conventional ski.

It might be mentioned here that the yoke 22, the link H2, as well as the chain 14 are all carried to the outside of the ski in this use of the ski. Thus when the ski of the present invention is being used as a conventional ski, these laterally projecting elements of one ski cannot interfere with the same elements of the other ski. When the ski is being used as a conventional ski, disconnects 33a can be removed from the axles 34 to permit the flexible shafts 33 to be stowed in any position desired on the pack 32. Thus with the flexible shafts 33 disconnected from the axles 34, the ski is freed, of the restraint of the flexible shafting while the skier is executing downhill maneuvers. A skier may thus glide down through the action of gravity over a snow covered terrain in exactly the same manner as he would if he was equipped with conventional skis.

With the ski of this embodiment, once he has reached the lowermost extent of the terrain over which he has glided and now wishes to climb an upwardly inclined surface, he may, by retracting the pair of spring-urged locking pins 33, pivotally move the fore and aft ski segments I9 and '2I of each ski about the axis established by the bolts 26 to bring the belts 31 and 92 into engagement with the terrain up which he desires to climb. The pins 39 will snap intothe openings formed at the opposite sides of the flanges Z Ito hold the ski segment in the desired position with the belts 3'! and 92 in their operative driving positions. The motor 3| can now be started to drive the sprocket member 41 of thepulley 35 which in turn drives the belt 37. The belt 92 is, of course, simultaneously driven through the sprocket II and chain I4 which is passed about the sprocket I5 carried by the axle 1'6 to which the'pulley is fixed.

- In this particular use of the embodiment of the invention now being described, the boot I I of the skier is held close to the terrain so that the center of gravity is maintained low. This is the preferred position for hard packed snow or at least snow into which the skis do not sink to any appreciable extent as the skier moves over the same. As the skier will sink into the snow to some extent, means are preferably provided to reduce the drag of the binding plate as the ski is moved forwardly through the action of the driving belts. This means, in the now preferred embodiment of the invention, comprises a fairing member H4 fixed to the gusset plate 23 cf the leading edge of the yoke 22 through bolts or some similar fastening means. It will be seen, referring again toFigure 11, that the leading face of the fairing member ,I I4 is smoothly curved and fairs into the gliding surface 2!! of the binding plate'IO. vIt should be obvious that the fairing member I I4, because of its particular location and contour, will tend to reduce the drag which otherwise might have been caused by the binding plate and its mounting means.

The outer surface of each driving belt is preferably'formed withsome traction inducing means and each belt may, if desired, comprise a plurality of bristle-like elements embedded within the outer surface thereof.- In one form of the belt, referring nowto Figure 25, these bristle-like elements might consist of short, relatively rigid strands II5 of a suitable plastic, such as nylon, anchored within the material of the belt I I6 during the operation of forming the same. The bristles should extend obliquely and rearwardly to the surface of the belt to the end that they would not materially impede forward gliding movement of the skis if the belts were engaging the terrain, but would bite into the snow covered surface where the belt was actually being used to drive the skis forwardly.

, In Figure 26 there is shown a modified form of the driving belt in which the belt comprises an endless loop Ill of an elastically deformable material to the outer surface of which is secured a second loop II8 of sealskin, such as is used today to formthefclimbers previously mentioned- The hair bristles II9 of the sealskin, in this embodiment ,of the belt, perform the same function in exactly'the same way as the plastic bristles of the previously described embodiment of the belt.- I

The bristles of either form of the driving'belt will tend topick up and carry snow and, to prevent this snow from packing or accumulating between the one stretch of the belts and the adj acentfaces of the ski'segments forming the body member, it is now preferred to mount between pulleys 86 and t8 and the adjacent surfaces ,of the ski segments I9 and H, respectively, small scrapper blades I26, preferably V-shaped, as clearly shown in Figure 5. These. blades will remove snow from the bristles of each of the belts as the belts move around pulleys 86 and'38. The scrapper blades I2Il can be mounted either to the brackets I8 and 39 or to the ski segments so long as'they act to remove snow from the belts asthey are carried around the pulleys. Q I j If it is desired to providemeans for preventing the entry 'of snow between the two stretches of each belt, cover elements can be provided which would consist of plate-like elements I2I, preferably secured to the upper and lower edge faces respectively of the longitudinally extending elements I04 and B1 of the frames 85 and 65, respectively. These cover plates have been shown in Figures 7 and 8 only, as their inclusion in the other figures of the drawing would obviously complicate the disclosure of elements carried between the two stretches of the belt.

It will now be seen that the belts, as they are driven in the direction necessary to force each ski forwardly, will carry the skier forwardly and upwardly of the slope with little, if any, exertion on his part. As the traction surfaces of the belt do not impede forward movement of the belt, the ski segments do not have to be inverted if the skier, because of the terrain, is required to glide forwardly and downwardly over a relatively short inclined slope. This is done by merely gliding downwardly with the belts in engagement with the snow covered surface of the slope in exactly the same manner as he would if the gliding surfaces were engaging the terrain.

It might be mentioned here that the extreme forward tip of the skis of the present invention are reversible so that the extreme tip portions may be adjusted so as to extend upwardly regardless of whether the belts are engaging the snow covered terrain or whether the skis are being used with the gliding surfaces in action. Although a number of different means can be used for reversing the tip of the ski, in the embodiment of the invention now preferred, the extreme tip portion of the ski segment I9 is formed as a separate member I23 which is detachably mounted to the segment.

The means used to mount the tip member I23 may comprise a pair of plates I24 secured to the opposite edge faces of the tip member I23 by conventional securing means. The plates I24 extend beyond the inner face of the tip member I23 and the extending portions are each formed with a slot I25 extending inwardly from the free edge thereof. The slots I25 are adapted to receive pins I26 projecting outwardly from the opposite edge faces of the ski segment I9 and the pins coact with the defining edges of the slots I25 to align the tip member I23 with the ski segment I9.

The segment carries within suitable channels a pair of pins I21 mounted for sliding movement transversely of the ski segment. The opposite or outer ends of the pins I21 are adapted to be engaged in openings formed in the extending portions of the plates I24. Springs, not shown but carried within the channels within which the pins are mounted, normally urge the pins outwardly and into engagement with the openings formed in the plates I24. Thus it will be seen that when the pins I21 are engaged or received in the openings of the plates I24 the tip member I23 will be rigidly held to the ski segment.

To reverse the relative positions of the ski seg ment and tip, the pins I2! can be easily retracted by merely forcing together the actuators I28 lat erally projecting from the pins I21 and slidable in L-shaped slots I29 formed in the one face of the ski segment 19. Once the pins I21 are retracted and are no longer engaged in h p ings in the plates I24, the tip member can be separated from the ski segment by an axially pp d c i verted. and a ain m n d t th se men To h ld the pigs 1.21 in hei retracted position during the inverting operation,

the actuators I28 can be moved into the laterally extending legs of the slots I29. After the tip member has been inverted and again mounted to the ski segment, merely moving the actuators out of the laterally extending legs of the slots I29 will permit the springs to move the pins l2? into engagement with the openings formed in the plates I24.

If desired, the leading edge of the ski segment I9 can be formed with a tongue or tenon ISI which is adapted to engage in a groove or rabbet formed in the adjacent face of the tip member I23.

With the tip member I23 removable for the purpose of inverting the same relative to the ski segment, the tip member can be mounted to extend upwardly when the gliding surfaces of the ski segments are in action as well as when the driving belts are being used to propel the skis forwardly. This feature of the ski of the em bodiment now being described will be best understood from a comparison study of Figures 6 T of the drawing.

With the traction belts 31 and E2 engaging the snow covered terrain, it should be appreciated that the power output from the motor 3I will drive the skis forwardly over the snow covered terrain. All of the power transmitted by each flexible shaft 33 to each ski is taken by the axle 34 and thus the driving forces are directly transmitted to the ski by the bracket 36 which di rectly supports the axle 34 for rotation. The driving forces transmitted to the belt 3'! by the sprocket wheel 41 and chain 52 are not transmitted to the ski through the bracket 39 for it will be remembered that the axle 55 is not fixed to the bracket 39 but rather to the arms 64 of the frame 65. The axle 56 actually floats relative to the bracket 39 as the elongate openings 58 permit the axle 56 to move relative to the bracket.

All driving forces created therefor by the belt 3'5, which might be likened to pushing forces urging the ski segment forwardly, are transmitted to the ski segment through the bracket 36. This is also true of the forces created by the beit 82 for neither axle i6 nor I08 is immovably held by the brackets 78 and IE2, respectively, but rather by the frame member 85 interconnecting and rigidly fixing the distance between the axles 76 and IE0. This is so for :both axles I5 and 166 can simultaneously move relative to their respective brackets because of the elongate openings of the brackets through which the opposite ends of the axles project. Reaction forces getc erated by driving movement of the belt 92 are, therefore, transmitted to the frame 35 and from the frame 85 to the bracket 36 by the stresscarrying link I I2 which fixes the distance between the axles l6 and 34. Thus the forces propelling the ski forwardly due to engagement of the belt 92 with the snow surfaces, which forces can be likened :to pulling forces which pull the for wardly, are also taken by the bracket 33.

This structure is used to render the entire ski flexible so that the ski may flex as it moves over irregular terrain. It should ;be appreciated that if the axles 56, 3e, 76, and I00 were supported directly by their respective brackets, the ski would be extremely rigid for then the brackets and the irame members would form a truss-like structure which would reinforce the ski against bending moments and prevent the ski from flexing as it moved ove terrain which was not a substantially pl na ur Thus if th? ski of the present invention is being I3 used as a conventional ski, that is, with the gliding surfaces 21, 29, and 28 engaging the snow, both the fore and aft segments may flex, as well as the plate I9, in exactly the same way as conventional skis will flex as they move over irregular surfaces.

This feature of the present invention is, of course, also had where the traction belts 31 and 92 are engaged with the snow surface and are being used to propel the ski forwardly. The skis are not subjected to the sam bending or flexing forces when the belts are being used to propel the ski forwardly for the belts, as they are pliant, will tend to assume the shape or contour'of the surface over which they .are moving. The purpose and function of the resiliently mounted idler pulleys I I6 should now be clearly understood for these pulleys obviously will tend to hold the belts 92 and 31 in good driving engagement with the surface of the snow regardless of the particular contour of the surface.

In the previous description of the use of the embodiment of the ski now being described, the position of the toe iron It was not changed relative to the binding plate I9 when the ski segments were pivotally moved relative to the binding plate. In this use of the ski, it will be remembered, the binding plate occupied the position shown in Figure i of the drawing. As the toe iron is detachably mounted to the binding plate and as it can be attached to either face of this plate, the toe iron can :be removed from the binding plate and attached in the position shown in Figure 19. In this use of the ski of the present invention, during the time the driving or traction belts are in use, the boot H of the skier is held at a relatively greater distance above the surface of the snow than in the use of the ski illustrated in Figure 4 of the drawing. The ski could be-so used in relatively deep powder snow and into which the skis would a'nk to a relatively great depth as the skier moved over the same.

There is shown in Figure 21 a modified form of the ski of the present invention in which elements identical in shape and purpose to elements previously described in connection with the embodiment of the invention shown in Figure 1 have been given the same reference characters. In

this embodiment of the invention, the power source is actually carried by the skit itself and comprises a small gasoline motor I35 mounted to the frame I36 which is similar to and performs the same function as the frame member 65 of the previously described embodiment of the invention. The bracket I31, used to support the motor I35 on the frame I36, also supports a small flywheel and clutch I 39 which includes a driven shaft I39 supported fo rotation in bearings MI carried by the web member I42 of the frame 36. The driven shaft I36 carries at the free end thereof a worm I63 engaging and driving a gear I 44 fixed to a shaft I45. The shaft I 45 extends transversely of the frame I36 and is journaled at its opposite ends in bearing members I46 carried by the longitudinally extending members I41 of the frame I36. Fixed to the one end of the shaft I45 is a sprocket wheel I48, the teeth of which engage and drive a sprocket chain I 49 which is also passed around a sprocket wheel II fixed to the axle or shaft I52 rotatably supported by a bracket identical in all respects to bracket 36 of the earlier described embodiment of the invention.

The pulley member fixed to the axle I52 is identical to the pulley 35 and will not be again ,one face of the ski segment I62.

described. In fact, the remainder of the ski of the embodiment now being described is identical to the previously described embodiment of the invention and is used in the same manner. Actually, as should now be appreciated, the only difference between the embodiment of the invention now being described and that previously described is in the power source used to drive the traction belts. Not only is this power source carried by the ski, but the fuel supply as well. The fuel supply is held by a small tank I53 supported through brackets I54 on the frame member I36. Thus each ski includes a complete power source, the output of which can be conveniently varied through a throttle member I 55 which may be operated by the skier through some suitable shafting means not shown.

There is shown in Figure 23 a further modifled form of the ski of the present invention. In this form of the invention, the binding plate I69, to which the toe iron I6I is secured in the same manner as was the toe iron I2, is pivotally mounted between the ski segments I62 and I63 bypower transmitting means for transmitting power from an axle I86 to the axle I98. This power transmitting means comprises a shaft I66 passed through a longitudinally extending bore I61 formed in the bindingplate I69. The shaft IE6 is suitably journaled within the bore and carries at its opposite ends pinions I68 and I69 engaging gears HI and I12, respectively, housed within laterally extending flanges I13 formed at opposite ends of the binding plate I69.

The gears HI and I12 are carried by stub shafts I14 and I15, respectively, journaled within the flanges I13. The shaft I 15 extends rearwardly through a bore formed in a flange I16 forming a part of a bracket member I11 fixed to the one face of the ski segment I63. This shaft carries at the end extending beyond the flange I16 a bevel gear I19 which engages with a second bevel gear I19 carried by a shaft I8I journaled at its opposite ends in bearing members I62 carried by the bracket I11. Fixed to the one end of the shaft I8I is a sprocket wheel I83, the teeth of which engage a sprocket chain, schematically indicated at I84, and passed about a second sprocket wheel I85. The sprocket wheel I is fixed to an axle I86, identical to the axle 34, rotatably supported in a bracket I81, identical to bracket 36. As the pulley fixed to the axle I86 is identical to pulley 35, its structure will not again be described. The other elements associated with the ski segment I63 are also identical to the elements carried by ski segment 2i and, to simplify the disclosure of the embodiment now being described, reference is had to the description of the elements of ski segment 2|.

It will be seen that as axle I86 is rotatably driven, the sprocket chain I84 will drive the shaft ISI which shaft, through the bevel gears I19 and I16, will drive the elongate shaft I66. This shaft, it will be remembered, carries the pinion I68 engaging and driving the gear I1I fixed to the shaft I1 1. The shaft I14 is partially supported by a fairing member I 99 forming a part of a bracket member I89 secured to the Fixed to the end of the shaft I14 projecting beyond the leading face of the fairing member I83 is a bevel gear I9! which engages and drives a bevel gear I92 fixed to a stub shaft I93. The shaft I63 is journaled in a bearing member I96 carried by the bracket I89 and this shaft carries 'at'its outer end a sprocket wheel 195, the teeth of which engagev and drive a sprocket chain, schematically indicated at I56. The sprocket. chain it is also passed about a sprocket wheel I9? fixed to an axle I98, identical in all respects to the axle I6 of the previously described embodiment of the invention. The axle I83, like the axle it, carries a pulley identical to pulley 8% and identified .in Figure 23 by that reference character. A short stress-carrying link I59 having bearing members 200 at the opposite ends thereof engaged with the axle I38 and shaft I93, respectively, fixes the distance between the latter and maintains the chain I96 taut.

It should be seen now that as axle I36 is rotatably driven to drive the belt 32, the belt 82 will be sin'lultaneousl3 driven in the same direction through the drive connection just described to produce the same result as in earlier described embodiments of the invention.

The binding plate I 69 is actually supported for pivotal or rotational movement between the ski segments I52 and H53 bythe stub shafts lid and I15 and the binding plate I66 can be moved about the pivotal axis established by these shafts in exactly the same manner as was binding plate It movable about the axes established by the bolts 26. To hold the binding plate I69 in the desired position relative to the ski segments I52 and H53, spring-loaded pins, identical to the pins 39, are used. These pin actuators, identified in Figure 23 by the reference character 30' and pins 38, will hold the binding plate I68 in either one of two alternate positions corresponding to the alternate positions of binding plate It. It should be understood that when the binding plat-e IE6 is moved from one alternate position to the other, the ski segments IE2 and I53 are actually moved independently to present to the snow covered terrain either the conventional gliding surfaces formed on the one face of each segment as well as the binding plate Ifiil or the driving belts 31 and 92..

The ski of this embodiment of the invention can, therefore, be used in the same manner as the embodiment shown in Figure 1 and no further description of the manner of use of this form of the invention is believed necessary.

Although in most uses of the ski or this canbodiment of the invention, the ski will be used either as a conventional ski or with the segments 62 and I63 inverted to place the driving belts thereof in engagement with the snow covered surface. However, the ski of this embodiment can be used with one ski segment inverted with its driving belt in engagement with the snow covered surface while the other segment could be disposed with the gliding surface thereof engaging the surface. This is possible because of the particular power transmitting means here employed which PEI/mite independent pivotal movement or the ski segments I62 and H33.

In all of the embodiments of the present invention hereinbefore described, the body members forming the ski proper have consisted of the fore and aft segments together with the binding plate pivotally mounted intermediate the ends of the segments but many, not all, of the features and advantages of the forms of the invention hereinbefore described can be had by attaching a driving unit to a conventional ski with but few alterations. Such an installation is shown in Figure 2B of the drawing in which a conventional sk 3B is ho n with a riving n s mila to the driving unit shown in Figure 3 mounted 16 thereto. The driving unit can be either powered by a motor, such as that shown at Iii, or by a power unit actually carried by the driving unit and which has been previously described in connection with the embodi ent of the invention shown in Figure 21.

The driving unit of the embodiment of the invention shown in Figure 20 can be identical to the driving units previously described for it should be seen that as the brackets are all detachably mounted to the body of the ski, the entire driving unit could be bodily removed from either the ski of the embodiment shown in Figure 2 or Figure 2i and mounted to a conventional ski, such as illustrated at 26L In fact the only modifications to the ski would be the provision of the spring mounted pins 42 for mounting the flanges ll to the ski body and the addition of the pins 11 for mounting the toe iron I 2 to either face of the ski 201. To simplify the disclosure of this form of the present invention, all elements thereof identical to elements previously described have been given the same reference characters.

A conventional ski, odified as above mentioned and carrying the driving unit, could be used in exactly the same manner as are the other embodiments of the ski herein shown. With the ski in use as shown in Figure 20, the driving belts 3'1 and 92 would propel the skier forwardly in exactly the same manner as hereinbefore described. In such a use of this form of the invention, the toe iron I2 would be mounted in such a position as to hold the boot II of the skier to the gliding surface of the ski and the boot would be held in substantially the same attitude as is the boot in the embodiment of the invention illustrated in Figure 13. When it was desired to use the ski with the gliding surfaces engaging the terrain, the toe iron I2 could be easily removed from the ski 2H and the entire ski inverted after which the toe iron would be again placed in its conventional position and the skis would be then ready for use to glide downwardly a a conventional ski.

In all forms of the invention hereinbefore described, the driving belts have comprised elastically deformable loops in which the bristles were embedded or to which sealskin or other similar animal hide was secured. The belts must be slightly deformable because of the particular manner in which the sprocket chains were secured to their undersurface. It will be seen, referring now to Figure 8, that the sprocke chain there shown is actually displaced inwardly from the traction belt so that as the belt and the sprocket chain fixed thereto travels about either of the pulleys over which the belt is running, there will be a difference in the peripheral speeds of the belt and the sprocket chain. This is so for the radius of curvature of the path of movement of the belt and chain about the pulley will diner. If the body of the belt is elastically deformable, the difference in peripheral sp ed can easily be accommodated but if it is desired to form the belt of a material which is not elastically deformable, the sprocket chain must be fixed to the belt so that the belt and the chain move about the pulley at the same peripheral speed.

Such a belt is shown in Figures 2'? and 28 in which the belt is formed of a pair of belt sections 25; of some suitable material carrying bristles 203. The sprocket chain 20d is mounted between the adjacent edges or" the belt sections 232 h v sh ng e br cke s att ch to the 17 'ja'cent edges of the belt sections 202. The legs of the brackets 25 attached to the belt sections 202 are held spaced therefrom by small bushings 206 or the like sleeving the rivets 201 used to fix the bracket 205 to the belt sections 202.

It will be seen, referring specifically to Figure 28, that the angle brackets 255 so mount the sprocket chain 264 that the pivot pins 208 thereof are disposed in a plane which contains the transverse axes of the belt sections 262. Thus the belt formed by the sections 202 and the sprocket chain 204 will move at substantially the same peripheral speed as the belt moves about either of the pulleys supporting the belt for rotation. The belt formed by the sections 202 also carries on its inner face V-belts 209 which perform the same function as the V-belts of the embodiments of the driving belt previously described.

There is shown in Figures 29 to 31, inclusive, a

further modified form of the driving belts and the belt there shown, like the belt of Figure 27, is formed with the sprocket chain 2H3 lying in substantially the same plane as that of the transversely arranged, spaced lugs 2H interconnected through the angle brackets 2I2, including spacer bushings similar to those used in the embodiment of the belt sohwn in Figure 28, which mount the sprocket chain 210 and the V-belts 2l3 to form an endless driving belt. The lugs 2 are T- shaped in cross-section as is clearly shown in Figure 31. The shanks 2: of the lugs 2!! form spaced cleats extending transversely of the belt for improving the traction between the belt and the snow covered terrain engaged thereby.

Although the now preferred embodiments of the present invention have been shown and described herein, it is to be understood that the invention is not to be limited thereto, for it is susceptible to changes in form and detail within the scope of the appended claims.

I claim:

1. A power driven ski, comprising: a ski body member formed with a gliding surface; at least one endless belt having a traction surface; means for rotatably supporting said endless belt on said body member in superposed relationship to the surface thereof opposite to said gliding surface; means for mounting a skiers boot to said body member; said body member being invertible to move said gliding surface from a downwardly facing position engaging a snow covered surface to an upwardly facing position as said traction surface is moved into a downwardly facing position in which it is adapted to engage said snow covered surface; and power means for driving said belt for propelling the ski forwardly when thetraction surface of said belt is engaging the snow covered surface.

2. A power driven ski, comprising: a ski body member having one face thereof formed with a gliding surface; at least one endless belt having a traction surface; means for rotatably supporting said endless belt on said body member adjacent the face thereof opposite to said gliding surface; means for mounting a skiers boot to said body member; said mounting means being so arranged relative to said body member that said gliding surface is movable from an operative position engaging a snow covered surface as said traction surface is moved into an operative position to engage said snow covered surface; and power means for driving said belt for propelling the ski forwardly when'the traction surface of said belt is in an operative position in engagement with the snow covered surface.

3. A ski of the type described, comprising: a body member having a gliding surface coextensive with one surface thereof for supporting the ski on a snow covered terrain; a pair of endless belts; a pair of pulleys over which each belt runs; bracket means for removably mounting each pulley to said body member in superposed relation to the surface of said body member opposite to said gliding surface and in spaced relationship therealong to mount said belts in superposed relationship to said body member and in longitudinally aligned relationship therewith; rigid means interconnecting each pair of pulleys, whereby the distance between the axes of rotation of adjacent pulleys remains constant; said bracket means including means for permitting at least one of each pair of said pulleys to move relative to said body member as the latter flexes in traveling over irregular terrain with the gliding surface of the body member in engagement therewith; and means for driving said belts, whereby said belts, when the latter are disposed in engagement with the snow covered terrain, will propel said ski forwardly thereover.

4. A ski of the type described, comprising: a body member including a pair of ski segments each formed with a gliding surface; a rigid member holding said segments apart in a 1ongitudinally aligned relationship; a plate to which the boot of the skier is to be mounted adapted to be mounted between said segments; a pair of endless belts; means for mounting a belt to each segment in superposed relation to the surface of the segment opposite to the gliding surface thereof; means for driving one of said belts; and means for transmitting power from said driven belt to the other of said belts, said transmitting means mounting said plate for pivotal movement relative to said segments whereby said segments are movable from a position in which the gliding surfaces thereof are engaging the snow covered terrain to an inverted position relative thereto in which said belts are engaging the terrain.

5. A ski of the type described, comprising: a body member including a pair of aligned ski segments each formed with a gliding-surface and pivotally interconnected by a plate to which the boot of the skier is to be mounted, said segments being invertable relative to said plate; a pair of endless belts; means for mounting a belt to each segment in superposed relation to the surface of the segment opposite to the glidmg surface thereof; an endless drive chain fixed to the inner surface of each of said belts; means, including means engaging one of said chains, for driving the belt to which said chain is fixed; and means for transmitting power from said driving means to the chain fixed to the other of said belts, said segments being movable from a position in which the gliding surfaces thereof are engaging the snow covered terrain to an inverted position relative thereto in which said belts are engaging the terrain and operative, when driven, to drive the ski forwardly thereover.

6. A power driven ski, comprising: a binding plate to which the boot of the skier is adapted to be detachably clamped; a ski segment extending rearwardly of said plate, a ski segment extending forwardly of said plate; said segments being longitudinally aligned and each segment being formed with a polished surface for gliding over snow covered terrain; means for mounting said plate intermediate said ski segments for rotational movement about an axis coincident 

